Distinct generic parameter types

[def-]

type intorfloat = int or float # Adding distinct doesn't help

proc x(a: intorfloat; b: intorfloat) =
  echo a, " ", b

# Working
proc y(a: int or float; b: int or float) =
  echo a, " ", b

var c: float = 2.0
var d: int = 3
x(c, d)

I would expect this code to work, but get a type mismatch:

foo.nim(11, 1) Error: type mismatch: got (float, int)
but expected one of: 
foo.x(a: intorfloat, b: intorfloat)

On a related note, maybe this is also supposed to work:

proc z[T1, T2: int or float](a: T1; b: T2) =
  echo a, " ", b

But it seems to suffer from the same problem.

[oprypin]

Got another example (seems more similar than I initially thought)

type
  A*[T] = distinct T
  B*[T] = distinct T

  AB*[T] = A[T] or B[T]

proc `==`*[T](x: distinct AB[T], y: distinct AB[T]): bool =
  true

var a: A[string]
var b: B[string]
assert(a == b)

(12, 9) Error: type mismatch: got (A[system.string], B[system.string])
but expected one of:
a0.==(x: distinct AB[==.T], y: distinct AB[==.T])
system.==(x: pointer, y: pointer)
etc etc

[demotomohiro]

This bug is still not fixed.

In Nim manual, there is following example code: https://nim-lang.org/docs/manual.html#generics-implicit-generics

proc p(a: Table, b: distinct Table)

# is roughly the same as:

proc p[Key, Value, KeyB, ValueB](a: Table[Key, Value], b: Table[KeyB, ValueB])

But this code results in compile error.

import tables

proc p(a: Table, b: distinct Table) =
  discard

proc p2[Key, Value, KeyB, ValueB](a: Table[Key, Value], b: Table[KeyB, ValueB]) =
  discard

var
  x: Table[int, string]
  y: Table[string, int]

# p2 works
p2(x, y)

# Compile error:
p(x, y)

/home/jail/prog.nim(17, 2) Error: type mismatch: got <Table[system.int, system.string], Table[system.string, system.int]>
but expected one of:
proc p(a: Table; b: distinct Table)
  first type mismatch at position: 2
  required type for b: CompositeTypeClass
  but expression 'y' is of type: Table[system.string, system.int]

expression: p(x, y)

Nim devel version:

Nim Compiler Version 1.5.1 [Linux: amd64]
Compiled at 2021-10-12
Copyright (c) 2006-2021 by Andreas Rumpf

git hash: 83128f217f63045974a48e61b65386abbfc97352
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